Field of the Invention
The present invention relates to a new and useful device which automatically adjusts the tension in prestressed wire used in conjunction with an apparatus for prestressing concrete structures or the like, such as reservoirs, nuclear reactor housings, pipe and pressure vessels in general.
It is a commonly used practice to wrap or bind concrete tanks with a continuous spiral of wire which maintains the wall of the tank under prestressed compression at all times regardless of variations in internal hydraulic pressure as the tank is filled or emptied. It is therefore of extreme importance that all wire to be wrapped around the tank be wrapped at a tension within a precise tolerance range.